Hard coating, hard-coated member and its production method, and target for producing hard coating and its production method

a production method and technology for hard coatings, applied in the direction of manufacturing tools, turning machine accessories, superimposed coating processes, etc., can solve the problems of nitride coatings not having oxygen, hard alticrno coatings having al—o bonds exceeding an inevitable impurity level, and hard alticrno coatings of jp 3877124 b do not have sufficient oxidation resistance and wear resistance to meet, etc., to achieve improved oxidation resistance and wear resistance, long life

Inactive Publication Date: 2018-12-13
HITACHI TOOL ENG LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The patent is about a new type of hard coating that is better than conventional coatings at resisting oxidation and wear. The coating is made of polycrystalline grains of Al-rich (AlTiM)NO with M-O bonds, which are stronger than Al—O bonds. This makes the coating stronger and more durable than traditional coatings. The method for producing the coating ensures that the structure of the coating is stable and efficient. The hard-coated members made from cemented carbide, ceramics, high-speed steel or tool steel with this coating have improved performance compared to conventional coatings, making them useful in applications such as cutting tools and dies.

Problems solved by technology

However, because the method of JP 3877124 B uses an oxygen-containing atmosphere, oxygen in the atmosphere is predominantly reacted with Al, resulting in a hard AlTiCrNO coating having Al—O bonds exceeding an inevitable impurity level.
Accordingly, the hard AlTiCrNO coating of JP 3877124 B does not have sufficient oxidation resistance and wear resistance to meet recent demand of high performance for cutting tools, etc.
However, because the targets [C1 (for example, Ti100), C2 (for example, Al70Cr30) and C3 (for example, Ti75Si25)] used do not contain oxygen in an amount exceeding an inevitable impurity level, the resultant hard nitride coatings do not contain oxygen in an amount exceeding an inevitable impurity level, failing to sufficiently exhibit targeted oxidation resistance and wear resistance.
In the method of JP 2008-533310 A, however, oxygen is introduced from an atmosphere gas using a target containing no oxygen, so that the resultant hard coating has Al—O bonds exceeding an inevitable impurity level, failing to exhibit sufficient oxidation resistance and wear resistance.

Method used

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  • Hard coating, hard-coated member and its production method, and target for producing hard coating and its production method
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  • Hard coating, hard-coated member and its production method, and target for producing hard coating and its production method

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0123](1) Cleaning of Substrate

[0124]High-feed milling insert substrates (EDNW15T4TN-15 available from Mitsubishi Hitachi Tool Engineering, Ltd., each having a main cutting edge 35 and a flank 36 shown in FIG. 13) 30, and property-evaluating insert substrates (SNMN120408 available from Mitsubishi Hitachi Tool Engineering, Ltd.), which were made of WC-based cemented carbide having a composition comprising 6.0% by mass of Co, the balance being WC and inevitable impurities, were set on an upper holder 8 in the AI apparatus shown in FIG. 1, and heated to 600° C. by a heater (not shown) simultaneously with evacuation to vacuum. Thereafter, with an argon gas in a flow rate of 500 sccm introduced into a vacuum chamber 5 to adjust the pressure to 2.0 Pa, and with DC bias voltage of −200 V applied to each substrate, each substrate was cleaned by etching with argon ion bombardment. The term “sccm” means a flow rate (cc / minute) at 1 atm and 25° C.

[0125](2) Formation of Modifying Layer Using Ti...

example 10

[0164]An (AlTiCr)NO coating was formed on the same WC-based cemented carbide substrate as in Example 1, and evaluated in the same manner as in Example 1, except for forming no modifying layer. As a result, the tool life was 28 minutes, longer than that in Comparative Example 1.

example 11

[0165]In the AI apparatus of FIG. 1, a target 10 having a composition of Ti0.8B0.2 (atomic ratio) was set on the arc discharge evaporation source 13 connected to the arc discharge power source 11, and the same high-feed milling insert substrate and property-evaluating insert substrate of WC-based cemented carbide as in Example 1 were placed on the upper holder 8. Each substrate was cleaned with argon ions in the same manner as in Example 1. A modifying layer having an average thickness of 5 nm was then formed on each substrate kept at 610° C. at an argon gas flow rate of 50 sccm, with DC bias voltage of −750 V applied to each substrate from the bias power source 3, and with DC arc current of 80 A supplied to the target 10 from the arc discharge power source 11. An (AlTiCr)NO coating was subsequently formed on the milling insert and evaluated in the same manner as in Example 1. As a result, the tool life was 56 minutes, longer than that in Example 1 (53 minutes).

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PUM

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Abstract

A hard coating having a composition represented by (AlxTiyMz)aN(1-a-b)Ob, wherein M is at least one element of Cr and Nb, and x, y, z, a and b are numbers meeting by atomic ratio 0.6≤x≤0.8, 0.05≤y≤0.38, 0.02≤z≤0.2, x+y+z=1, 0.2≤a≤0.8, and 0.02≤b≤0.10, respectively, having M-O bonds without Al—O bonds exceeding an inevitable impurity level as a bonding state identified by X-ray photoelectron spectroscopy, and having only an NaCl-type structure in its X-ray diffraction pattern.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a hard (AlTiM)NO coating having excellent oxidation resistance and wear resistance, a hard-(AlTiM)NO-coated member and its production method, and a target used for producing a hard (AlTiM)NO coating and its production method.BACKGROUND OF THE INVENTION[0002]To provide long lives to tools for cutting works at a high feed or speed, dies used under severe molding conditions, etc., various hard coatings having excellent oxidation resistance and wear resistance have been proposed. For example, JP 3877124 B discloses a hard AlTiCrNO coating comprising at least Al, Ti, Cr, N and O, the non-metal component being NwO100-w, wherein w is 70-99 atomic %, and having a multi-layer structure comprising a layer A having an oxygen content of 1-10 atomic %, and a layer B having an oxygen content of more than 10 atomic % and 30 atomic % or less. JP 3877124 B describes that the oxygen content in the AlTiCrNO coating is controlled by using a m...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): C23C14/32C23C30/00C23C14/06C23C14/02
CPCC23C14/325C23C30/005C23C14/0676C23C14/02B23B27/14C23C28/044C04B35/581C23C14/024C04B2235/3886C04B35/62615C04B35/645C04B2235/3232C04B2235/3865C04B2235/3869C04B2235/402C04B2235/404C04B2235/5445C04B2235/5454C04B2235/6581C04B2235/762C04B2235/77B22F3/02B22F3/12C22C1/05C22C29/12C22C29/16B22F2998/10B22F2999/00C22C1/0416
InventorFUWA, RYOUTAROUKUBOTA, KAZUYUKIFUKUNAGA, YUUZOH
OwnerHITACHI TOOL ENG LTD